i don't think that's true, because the majority of people are heterosexual.
If what you said was true, that would throw stats way off. JMO
Notice I said "abuses," because the abuse spectrum is not only sexual. Same gendered teachers is not a tool to preventing abuse. Giving teachers the tools to spot, report, and be proactive when seeing crossed boundaries...is. Schools taking reports of boundary crossing seriously and having systems in place, prevents abuse. Having classroom rules and disciplining teachers who break them, prevents abuse. Educating teachers about red flags and behavior indications, prevents abuse. There is so much that can be done, that just isn't. There are all kinds of productive ways to prevent abuse, but same gendered teachers is not one of them. That hurts everyone, actually. It lulls schools and students into a false sense of protection, and students miss out on the perspective and talents of good teachers.
And...someone doesn't have to be homosexual to abuse a student of the same gender. Most pedophiles identify as straight, and many predators look for an easy victim...not a gender.
I work with abuse victims, and these myths about abusers only protect them and not the victims.